<%= fields_for("response[all_answers][#{answer_counter}][all_choices][]", choice) do |f| %>
  <% f.mode = form_mode %>
  <%= f.hidden_field(:answer_id, :index => choice_counter) %>
  <%= f.hidden_field(:option_id, :index => choice_counter) %>
  <%= f.check_box(:checked, {:index => choice_counter}) %>
  <%= f.label(:checked, choice.option_name, :index => choice_counter) %><br/>
<% end %>